Balloon



N0v.3o,1948. J. A. HAEN mL l -v 42,455,241;

BALLooN Filed Oct. 25. 1944 Patented Nov. 30, 1948 BALLooN John A. Hagen, Glen Rock, Laurence Prendergast, Passaic, and Edmund L. Gregor, Ramsey, N. J., assignors to Molded Latex Products, Inc., Passaic, N. J., a corporation of New Jersey Application October 25, 1944, Serial No. 560,240 3 claims. (cl. 244-31) I This. invention relates to a barrage balloon. The balloon is made up of a casing of strong flexible non-elastic material and a leak-proof inflatable lbladder which is provided with end pieces of rigid solid material, such as metal.

The outer skin or casing is made of gussets or strips of cloth such as nylon sewed together and the bladder is seamless rubber. When iilled with gas the balloon will lift a weight which is as great or greater than itself to a height of several hundred feet under normal atmospheric conditions. The wall of the bladder may be about five to eight thousandths of an inch thick when uninflated and the body portions about one-to-one and a half thousandths of an inch when inated, While the end'portions are not so thin as the body portions are when inflated, for a purpose to be explained.

Conventional barrage balloons consist of an envelope made up of a layer or layers of fabric coated or impregnated with rubber or rubber-like substance-s and securely seamed and cemented at the seams to make them gas-tight. This makes a bulky balloon which has a dead weight free lift ration of 2 to 1 or higher.

One of the objects of this invention is to obviate the difliculties encountered with the older sorts of balloons, and to make one which, while light, will be -comparatively rugged to withstand the forces encountered in use and at the same time will have a dead weight free lift ratio of less than 2 to 1. To accomplish these ends our balloon has both a thin-walled and seamless rubber bladder and a casing, this casing being preferably of light'strong fabric such as nylon. It has been found in practice that such a balloon can lift a greater weight than the conventional fabric balloons of the same cubic capacity.

Furthermore, it has heretofore been impractical or unknown to make seamless rubber bladders in the shape of albarrage balloon and of such size as would provide appreciable lifting capacity and at the same time be impervious to gases and be r'ged. Y

" invention may be understood from the descriptionin connection with the accompanying drawing in which Fig. 1 is a section through a cylinder and container that may be used in forming the bladder;

Fig. 2 is a section showing the bladder removed and metal discs in place;

Fig. 3 is a side view of the bladder on a smaller scale showing a part of the process;

Fig. 4 is a section showing how a metal disc 4 is permanently attached to the bladder; and

- Fig. 5 is a bottom view of the completed device.

In carrying out the invention either natural orsynthetic rubber may be used for making the bladder. vThe invention will be particularly described in connection with the use of sunlightresistant neoprene latex for making the bladder.

An aluminum cylinder I' which may for example be about a foot in diameter, six feet long and have a wall thickness of about a quarter of an inch, has its inner surface smooth and polished. End plates 2 and 3 are provided for closing the ends of this cylinder and may be kept in place by Wing nuts 4.

4000 c. c. of neoprene latex compound which has been made heat-sensitive by the addition of 480 c. c. of approximately 10% aqueous ammonium nitrate solution is introduced into cylinder l and the end plates 2 and 3 are clamped in place. Cylinder I is then placed on bearings 5 on container 5 so that the longitudinal elements of its inner surface are horizontal. Container 6 has previously been filled with Water at 140-180 F. to such a height that cylinder l is immersed to a depth of several inches, thereby heating cylinder I and its contents. As soon a-s cylinder I is placed on bearings 5 it is rotated at a speed of 10 to 20 R. P. M.'to distribute the latex uniformly over its inner surface. The rotation is continued until all of the latex compound has gelled. The heat of the water in container 6 is transferred through cylinder I to the latex compound which gels in thin layers which build up one on another until all of the latex compound is gelled to a cylinder of uniform Wall thickness. This requires about two minutes. The cylinder may be rotated at a 'speed'off200 .t0.500 R. P. M., thereby distributing the latex compound to a uniform layer by centrifugalforce. The mold is then cooled to room temperature which may be done by rotating it in a similar way in cold water.

The soft exible cylindrical gel L is then removed from the mold.

Aluminum discs 8 and 9, Fig. 2, are then attached tothe open ends of the cylindrical gel L to close them. One of these discs is provided with a central opening I0 through which air may be introduced by a nozzle for inflating the cylinder.

The discs 8 and 9 are provided with inwardly extending flange-s II having annular grooves I2 around them. 'Ihe ends of the cylinder L overlap these anges and are bound in place by wrapping cloth tape I4 around where the grooves I2 are located. Cords I'5 may then be wrapped around the tapes and tied in place.

The cylindrical gel or bladder is then inflated by introducing air from a nozzle I6 (Fig. 3) that ts in the hole I while the bladder rests upon a flat surface such as the floor or a table. In order to prevent Weak or thin spots that may be present in the bladder from inating too rapidly and bursting before other parts are sufficiently inflated, non-elastic clothgirdles, such as `:the one indicated at I8, that may be made of 'cheesecloth for example, are put on the inflated bladder I9 to restrict the diameter to which expansion `is permitted to about five feet. Each of the girdles may be about three feet long and the rst one is placed over the portion ofthe bladder tha-t'first reaches about a ve foot diameterduring fthe iniiating operation. Other girdleS, not shown on the drawing, are added as the inflation proceeds With edges overlapping aboutlthreexinches @until the bladder is sufficiently inflated. During the inflating time the bladder is` turned so that different portions rest upon the floor as the inflation proceeds.

The position of the'first inflation bulge is controlled vby pressing by hand upon places Where the bulge is not desiredwhile the air is being introduced. It is desirable to cause the first bulge to'appear near the centeras this causes the thickness Yof the cylindrical portion of the Wall to be more-uniform and reduces the danger of the bladder-bursting :during the introduction of the air.

-By this process lthe -bladder is inflated with su stantially -even Wall thickness and uniform diameter along the cylindrical portion thereof leaving the Vend portions with greater thickness particularly-Where they are attached to the discs 8 and yil, thus reducing the danger of rupture where the discs are attached. 'The bladder is then about five feet in diameter and about twenty-six feet long. The bladder is then permitted to dry in the vair for afew hours. 'It is `then partially deflat-ed and a thin lm of talc is applied inside and out-to-prevent portions ofthe surface thereof that might fbe brought into contact with other portions from adhering to veach other.

The aluminum Adiscs 18 and 9 are removed and the ibladderfmaybe pre-shrunk when desired by heating it tof50`70 C.' for about l5 minutes. V"Two .permanent Yaluminum discs, such as the disc '124 shown yin Fig. 4, each .havinga flange 26 corresponding to Athe flanges VII on discs 8 and 9 are securelyanchored inthe .openings at opposite ends of Athe bladder I9. Asindicated on a 'larger scale Fig. 4, this is done byv first wrapping'a few plies'of rubber tape 281 around in the groove inthelange 26 of eachzdisc 2li 4and then inserting i.

the Atwo flangesinto openings at opposite ends of thebladder I9, Where `the neoprene had already been'correspondingly shaped by flanges 'II to t i-nto'the annular grooves 3D in the anges 26. The ends of the bladder Vare cemented tothe rubber tapes v28 bymeans `of neoprene cement. Then layers of cord 32 are Wrappediaround theends of the bladder I 9 to hold the ,discs 24 :securely .in place with `their flanges` 26 ltting inithe corre*- spondinglygshapediends .ofthe zbladder.

The casing SSTzGFig. 5) for the kballoon 'is 'made of nylon which is not water or gas-proof. It consists of a cylindrical portion 35, a hemispherical head portion 36 and a truncated cone tail portion 31. It is provided with openings 39 in the tail and head portions respectively. The bladder I9 is introduced into the casing through the opening '38'in the tail portion. '.'Ilheforvvarddiscld of the bladder is pulled through' the opening in the nose 39 of the casing 33 and is fastened to the head end of the casing by a draw string that is tightened around the outside of the ange 26 of disc 24. The disc in the other end of the bladder I9 is secured in the endvSB of the casing in a similar Way. The balloon is inflated in the usual Way. The-nylon Ycasing 33 is made up of strips.

Fins 4I) connected by braces 4I are provided on the tail portion :of the balloon and an anchoring rope or cord of nylon, not shown, is attached to the balloon at several places 42 in the known way.

A flexible insert 44 extends longitudinally of thefcasing-S ivith'ritsiedges attached to vtl'iefetlges 45'. along longitudinal seams yin thisv casing. rTransverse elasticcords 4B are provided to `bring the edges-'closer together when needed iso/adjust the diameter of the leasing 533.

Whatlis claimed is:

.1. A'balloon comprising an .elongated casing-fof flexible material having a hemisphericalirhead portion,.a cone-shapedztail lportion and aacylindrically.shapedl intermediate portion, an clongated bladder of v.elastirz :material :in said vcasing,

Vdiscs of rigid .material having .longitudinally curved flanges projecting inwardlyii-nto saidzbl-adder at'the ,ends thereof 'and-held in .pl-ace by :cords Wrapped iaround. theiroutside of zthefends 'of' said bladder :end rhermetically'binding'the I,ends of 'said bladder to said flanges.

2. The balloon of claim 1 in which rubber etape is `install-ed in the grooves `vin .said curved flanges between the :ends tof 'said `bladder-and fsaidianges.

f3'. The :balloon yof fclaim l ,in A.which rubber-:tape is installed 'in :the g-rooves'nsaid curved .flanges between'the endsaof isaid-bladderfand said flanges and the ends of said bladder are cementedfto :said

rubber tape.

REFERENCES. L(TI-'LED The following references are of record `in fthe file'of kthis patent".

UNITED-STATES .PATENTS Germany Feb-9, 1923 

